The authors of the work used genetic data and data on the health status of 7,146 participants in the ELSA study conducted in England. The average age of the participants was 65 years. It was found that people who sleep five hours a day or less are 2.5 times more likely to suffer from depression. Scientists have made adjustments for education, well-being, smoking status, physical activity and chronic diseases, writes "Газета.rи ".
Then the use of genetic data allowed scientists to exclude the influence of the environment (for example, social and financial factors) on the results. So, scientists found that people with mutations associated with a predisposition to short sleep (less than five hours a day) were more likely to report symptoms of depression. This indicates a causal relationship between depression and short sleep.
At the same time, a genetic predisposition to depression did not increase the likelihood of a 5-hour sleep. This means that the reduction in sleep duration caused depression, and was not a symptom of it.
